Results for "Linda A. Zotti"

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A simple descriptor for energetics at fcc-bcc metal interfacesFeb 08 2018We develop a new and user-friendly method for calculating interface energies from first-principles. Our approach avoids problems that derive from the numerical differences between bulk and slab calculations, such as the number of k-points along the direction ... More
Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQJun 25 2015We describe the synthesis and single molecule electrical transport properties of a molecular wire containing a ${\pi}$-extended tetrathiafulvalene (exTTF) group and its charge-transfer complex with F4TCNQ. We form single molecule junctions using the in-situ ... More
Heat dissipation and its relation to thermopower in single-molecule junctionsJul 31 2013Motivated by recent experiments [Lee et al. Nature 498, 209 (2013)], we present here a detailed theoretical analysis of the Joule heating in current-carrying single-molecule junctions. By combining the Landauer approach for quantum transport with ab initio ... More
Geometrical and Physical Properties of Circumbinary Discs in Eccentric Stellar BinariesSep 06 2008In a previous work (Pichardo et al. 2005), we studied stable configurations for circumstellar discs in eccentric binary systems. We searched for "invariant loops": closed curves (analogous to stable periodic orbits in time-independent potentials) that ... More
Circumstellar and Circumbinary Disks in Eccentric Stellar BinariesJan 13 2005We explore test particle orbits in the orbital plane of eccentric stellar binary systems, searching for ``invariant loops'': closed curves that change shape periodically as a function of binary orbital phase as the test particles in them move under the ... More
The dramatic size evolution of elliptical galaxies and the quasar feedbackSep 26 2008Oct 21 2008Observations have evidenced that passively evolving massive galaxies at high redshift are much more compact than local galaxies with the same stellar mass. We argue that the observed strong evolution in size is directly related to the quasar feedback, ... More
Electron scattering in atomic force microscopy experimentsOct 13 2005It has been shown that electron transitions, as measured in a scanning tunnelling microscope (STM), are related to chemical interactions in a tunnelling barrier. Here, we show that the shape and apparent height of subatomic features in an atomic force ... More
The Stellar and Gas Kinematics of Several Irregular GalaxiesJul 23 2002We present long-slit spectra of three irregular galaxies from which we determinethe stellar kinematics in two of the galaxies (NGC 1156 and NGC 4449) and ionized-gas kinematics in all three (including NGC 2366). We compare this to the optical morphology ... More
The Measurement of Disk Ellipticity in Nearby Spiral GalaxiesMar 13 2001We have measured the intrinsic disk ellipticity for 7 nearby, nearly face-on spiral galaxies by combining Densepak integral-field spectroscopy with I-band imaging from the WIYN telescope. Initially assuming an axisymmetric model, we determine kinematic ... More
Cosmic Evolution of Size and Velocity Dispersion for Early Type GalaxiesJun 11 2010[abridged] Massive, passively evolving galaxies at redshifts z>1 exhibit on the average physical sizes smaller by factors ~3 than local early type galaxies (ETGs) endowed with the same stellar mass. Small sizes are in fact expected on theoretical grounds, ... More
Radio Observations of Star Forming Galaxies in the SKA eraDec 18 2014We have combined determinations of the epoch-dependent star formation rate (SFR) function with relationships between SFR and radio (synchrotron and free-free) emission to work out detailed predictions for the counts and the redshift distributions of star-forming ... More
The Stability of Perfect Elliptic Disks. II. A Minimal Streaming CaseApr 03 1998Two dimensional realizations of self-consistent models for the ``perfect elliptic disks'' were tested for global stability by gravitational N-body integration. The family of perfect elliptic disk potentials have two isolating integrals; time independent ... More
Enumerating Palindromes and Primitives in Rank Two Free GroupsFeb 19 2008Feb 12 2011Let $F= < a,b>$ be a rank two free group. A word $W(a,b)$ in $F$ is {\sl primitive} if it, along with another group element, generates the group. It is a {\sl palindrome} (with respect to $a$ and $b$) if it reads the same forwards and backwards. It is ... More
Enumeration of rational plane curves tangent to a smooth cubicJan 15 2007Jan 31 2007We use twisted stable maps to compute the number of rational degree d plane curves having prescribed contacts to a smooth plane cubic.
Separable Representation of Energy-Dependent Optical PotentialsDec 22 2015Background. One important ingredient for many applications of nuclear physics to astrophysics, nuclear energy, and stockpile stewardship are cross sections for reactions of neutrons with rare isotopes. Since direct measurements are often not feasible, ... More
Cutting Sequences and PalindromesMar 03 2008Jun 11 2008We give a unified geometric approach to some theorems about primitive elements and palindromes in free groups of rank 2. The geometric treatment gives new proofs of the theorems. Dedicated to Bill Harvey on his 65th birthday.
The Geometry of Two Generator Groups: Hyperelliptic HandlebodiesJan 21 2005For two generator free Fuchsian groups, the quotient three manifold is a genus two solid handlebody and its boundary is a hyperelliptic Riemann surface. The convex core is also a hyperelliptic Riemann surface. We find the Weierstrass points of both of ... More
Positivity of equivariant Gromov-Witten invariantsOct 26 2011Dec 15 2011We show that the equivariant Gromov-Witten invariants of a projective homogeneous space G/P exhibit Graham-positivity: when expressed as polynomials in the positive roots, they have nonnegative coefficients.
A Molecular Platinum Cluster Junction: A Single-Molecule SwitchFeb 26 2013We present a theoretical study of the electronic transport through single-molecule junctions incorporating a Pt6 metal cluster bound within an organic framework. We show that the insertion of this molecule between a pair of electrodes leads to a fully ... More
A model for lopsided galactic disksMar 12 1998Many disk galaxies are lopsided: their brightest inner parts are displaced from the center of the outer isophotes, or the outer contours of the HI disk. This asymmetry is particularly common in small, low-luminosity galaxies. We argue here that long-lived ... More
Winding and Unwinding and Essential Intersections in $\mathbb{H}^3$Oct 16 2015Jul 07 2016Let $G = \langle A,B \rangle$ be a non-elementary two generator subgroup of the isometry group of $\mathbb{H}^2$, the hyperbolic plane. If $G$ is discrete and free and geometrically finite, its quotient is a pair of pants and in prior work we produced ... More
Planar families of discrete groupsJan 25 2005Determining the space of free discrete two generator groups of M\"obius transformations is an old and difficult problem. In this paper we show how to construct large balls of full dimension in this space. To do this, we begin with a marked discrete group ... More
Equivariant quantum Schubert polynomialsOct 26 2011Feb 18 2012We establish an equivariant quantum Giambelli formula for partial flag varieties. The answer is given in terms of a specialization of universal double Schubert polynomials. Along the way, we give new proofs of the presentation of the equivariant quantum ... More
Resonant transport and electrostatic effects in single-molecule electrical junctionsJun 03 2015In this contribution we demonstrate structural control over a transport resonance in HS(CH$_{2}$)$_{n}$[1,4 - C$_{6}$H$_{4}$](CH$_{2}$)$_{n}$SH (n = 1, 3, 4, 6) metal - molecule - metal junctions, fabricated and tested using the scanning tunnelling microscopy-based ... More
Separable Representation of Multichannel Nucleon-Nucleus Optical PotentialsNov 17 2016One important ingredient for many applications of nuclear physics to astrophysics, nuclear energy, and stockpile stewardship are cross sections for reactions of neutrons with rare isotopes. Since direct measurements are often not feasible, indirect methods, ... More
Clustering of sub-millimeter galaxies in a self-regulated baryon collapse modelNov 17 2011May 03 2012We have investigated the Cosmic Infrared Background (CIB) anisotropies in the framework of the physical evolutionary model for proto-spheroidal galaxies by Granato et al. (2004). After having re-calibrated the cumulative flux function $dS/dz$ at $\lambda ... More
Black Hole and Galaxy Coevolution from Continuity Equation and Abundance MatchingJul 27 2015[abridged] We investigate the coevolution of galaxies and hosted supermassive black holes throughout the history of the Universe by a statistical approach based on the continuity equation and the abundance matching technique. Specifically, we present ... More
The Coevolution of Supermassive Black Holes and Massive Galaxies at High RedshiftDec 13 2013Jan 07 2014We exploit the recent, wide samples of far-infrared (FIR) selected galaxies followed-up in X rays and of X-ray/optically selected active galactic nuclei (AGNs) followed-up in the FIR band, along with the classic data on AGN and stellar luminosity functions ... More
Simulations of Galactic Cosmic Ray Impacts on the Herschel/PACS bolometer Arrays with Geant4 CodeJun 30 2008The effects of the in-flight behaviour of the bolometer arrays of the Herschel/PACS instrument under impacts of Galactic cosmic rays are explored. This instrument is part of the ESA-Herschel payload, which will be launched at the end of 2008 and will ... More
Carbon tips as electrodes for single-molecule junctionsSep 09 2011Nov 03 2011We study electron transport through single-molecule junctions formed by an octanethiol molecule bonded with the thiol anchoring group to a gold electrode and the opposing methyl endgroup to a carbon tip. Using the scanning tunneling microscope based break ... More
Orbits Supporting Bars within BarsNov 15 1999High-resolution observations of the inner regions of barred disk galaxies have revealed many asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital time-scales in the galaxy center are short, secondary ... More
Bars within Bars in GalaxiesDec 11 1998Inner regions of barred disk galaxies often include asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital timescales in the galaxy center are short, secondary bars are likely to be dynamically ... More
Carbon-fiber tips for scanning probe microscopes and molecular electronics experimentsMay 24 2012We fabricate and characterize carbon-fiber tips for their use in combined scanning tunneling and force microscopy based on piezoelectric quartz tuning fork force sensors. An electrochemical fabrication procedure to etch the tips is used to yield reproducible ... More
Triple Bars and Complex Central Structures in Disk GalaxiesJun 16 1999We present an analysis of ground-based and HST images of three early-type barred galaxies. The first, NGC 2681, may be the clearest example yet of a galaxy with three concentric bars. The two other galaxies were previously suggested as triple-barred. ... More
Regular Orbits and Periodic Loops in Multiply-Barred Galactic PotentialsApr 11 1997We show that non-chaotic multiply-periodic particle orbits can exist in a galaxy-like potential where a small fast-tumbling nuclear bar is nested inside a main bar which has a slower pattern speed. We introduce the concept of a loop: a one-dimensional ... More
An Imaging Survey of Early-Type Barred GalaxiesDec 04 2002This paper presents the results of a high-resolution imaging survey, using both ground-based and Hubble Space Telescope images, of a complete sample of nearby barred S0--Sa galaxies in the field, with a particular emphasis on identifying and measuring ... More
Double Bars, Inner Disks, and Nuclear Rings in Early-Type Disk GalaxiesMar 29 2002We present results from an imaging survey of an unbiased sample of thirty-eight early-type (S0--Sa), low-inclination, optically barred galaxies in the field. Our goal was to find and characterize central stellar and gaseous structures: secondary bars, ... More
M87: A Misaligned BL LAC?Nov 20 1997The nuclear region of M87 was observed with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) at 6 epochs, spanning 18 months, after the HST image quality was improved with the deployment of the corrective optics (COSTAR) in December ... More
Spectroscopic Cosmological Surveys in the Far-IRSep 28 2009We show the feasibility of spectroscopic cosmological surveys with the SAFARI instrument onboard of SPICA. The work is done through simulations that make use of both empirical methods, i.e. the use of observed luminosity functions and theoretical models ... More
The Photometric and Kinematic Structure of Face-On Disk Galaxies. I. Sample Definition, H-alpha Integral Field Spectroscopy, and HI Line-WidthsMay 14 2006We present a survey of the photometric and kinematic properties of 39 nearby, nearly face-on disk galaxies. Our approach exploits echelle-resolution integral-field spectroscopy of the H-alpha regions, obtained with DensePak on the WIYN 3.5m telescope ... More
AGN torus emission for a homogeneous sample of bright FSRQsOct 10 2014We have selected a complete sample of 80 flat-spectrum radio quasars (FSRQs) from the WMAP 7-yr catalog within the SDSS area, all with measured redshift, and have inspected their SEDs looking for evidence of an AGN torus emission. A SED fitting algorithm ... More
Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery ModesOct 14 2014Dec 08 2014We present the design, fabrication and characterization of cubic (3C) silicon carbide microdisk resonators with high quality factor modes at visible and near infrared wavelengths (600 - 950 nm). Whispering gallery modes with quality factors as high as ... More
Predictions for surveys with the SPICA Mid-infrared InstrumentJun 06 2015We present predictions for number counts and redshift distributions of galaxies detectable in continuum and in emission lines with the Mid-infrared (MIR) Instrument (SMI) proposed for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA). ... More
Exploring cosmic origins with CORE: gravitational lensing of the CMBJul 07 2017Lensing of the CMB is now a well-developed probe of large-scale clustering over a broad range of redshifts. By exploiting the non-Gaussian imprints of lensing in the polarization of the CMB, the CORE mission can produce a clean map of the lensing deflections ... More
Reality of non-Fock SpinorsJan 23 2003Feb 05 2003The infinite dimensional Clifford Algebra has a maze of irreducible unitary representations. Here we determine their type -real, complex or quaternionic. Some, related to the Fermi-Fock representations, have no real or quetrnionic structures. But there ... More
T Tauri Jet Physics Resolved Near The Launching Region with the Hubble Space TelescopeAug 05 2008We present an analysis of the gas physics at the base of jets from five T Tauri stars based on high angular resolution optical spectra, using the Hubble Space Telescope Imaging Spectrograph (HST/STIS). The spectra refer to a region within 100 AU of the ... More
Silent initial conditions for cosmological perturbations with a change of space-time signatureNov 02 2014Recent calculations in loop quantum cosmology suggest that a transition from a Lorentzian to an Euclidean space-time might take place in the very early Universe. The transition point leads to a state of silence, characterized by a vanishing speed of light. ... More
Upper and Lower Bounds on Long Dual-Paths in Line ArrangementsJun 11 2015Given a line arrangement $\cal A$ with $n$ lines, we show that there exists a path of length $n^2/3 - O(n)$ in the dual graph of $\cal A$ formed by its faces. This bound is tight up to lower order terms. For the bicolored version, we describe an example ... More
Polytope Lyapunov functions for stable and for stabilizable LSSJun 23 2014We present a new approach for constructing polytope Lyapunov functions for continuous-time linear switching systems (LSS). This allows us to decide the stability of LSS and to compute the Lyapunov exponent with a good precision in relatively high dimensions. ... More
The Equivariant Chow rings of quot schemesFeb 08 2006Jan 05 2007We give a presentation for the (integral) torus-equivariant Chow ring of the quot scheme, a smooth compactification of the space of rational curves of degree d in the Grassmannian. For this presentation, we refine Evain's extension of the method of Goresky, ... More
Pointed trees of projective spacesMay 14 2005Dec 05 2006We introduce a smooth projective variety $T_{d,n}$ which compactifies the space of configurations of $n$ distinct points on affine $d$-space modulo translation and homothety. The points in the boundary correspond to $n$-pointed stable rooted trees of ... More
Energy-Throughput Trade-offs in a Wireless Sensor Network with Mobile RelayMar 24 2014In this paper we analyze the trade-offs between energy and throughput for links in a wireless sensor network. Our application of interest is one in which a number of low-powered sensors need to wirelessly communicate their measurements to a communications ... More
Information measure for financial time series: quantifying short-term market heterogeneityOct 19 2017A well-interpretable measure of information has been recently proposed based on a partition obtained by intersecting a random sequence with its moving average. The partition yields disjoint sets of the sequence, which are then ranked according to their ... More
The Near-IR Spectrum of Titan Modeled with an Improved Methane Line ListFeb 13 2011Feb 17 2011We have obtained spatially resolved spectra of Titan in the near-infrared J, H and K bands at a resolving power of ~5000 using the near-infrared integral field spectrometer (NIFS) on the Gemini North 8m telescope. Using recent data from the Cassini/Huygens ... More
On the Correspondence between Display Postulates and Deep Inference in Nested Sequent Calculi for Tense LogicsMar 28 2011May 14 2011We consider two styles of proof calculi for a family of tense logics, presented in a formalism based on nested sequents. A nested sequent can be seen as a tree of traditional single-sided sequents. Our first style of calculi is what we call "shallow calculi", ... More
Revisiting the Black Hole Masses of Soft X-ray-Selected Active Galactic NucleiNov 27 2006Mar 27 2007In our previous work, using luminosity and the H-beta FWHM as surrogates for black hole mass (M_BH), we compared the black hole masses of narrow-line Seyfert 1 galaxies (NLS1s) and broad-line Seyfert 1 galaxies (BLS1s) in a sample of soft X-ray-selected ... More
Ballistic emission spectroscopy and imaging of a buried metal-organic interfaceJan 04 2005The silver-p-phenylene (Ag-PPP) interface is investigated using ballistic electron emission microscopy (BEEM). Multiple injection barriers and spatial nonuniformity of carrier injection over nanometer length scales are observed. No unique injection barrier ... More
The Evolution of Viscous Inclined Disks in Axisymmetric and Triaxial GalaxiesDec 19 1995We have used a set of equations developed by Pringle (1992) to follow the evolution of a viscous twisted disk in a galaxy-like potential which is stationary or tumbling relative to inertial space. In an axisymmetric potential, the disk settles to the ... More
A Supermodular Optimization Framework for Leader Selection under Link Noise in Linear Multi-Agent SystemsAug 04 2012In many applications of multi-agent systems (MAS), a set of leader agents acts as a control input to the remaining follower agents. In this paper, we introduce an analytical approach to selecting leader agents in order to minimize the total mean-square ... More
Paired teaching for faculty professional development in teachingJul 21 2015Jul 04 2016Paired (or co-)teaching is an arrangement in which two faculty are collaboratively responsible for all aspects of teaching a course. By pairing an instructor experienced in research-based instructional strategies (RBIS) with an instructor with little ... More
Cut-Elimination and Proof Search for Bi-Intuitionistic Tense LogicJun 24 2010Jun 29 2010We consider an extension of bi-intuitionistic logic with the traditional modalities from tense logic Kt. Proof theoretically, this extension is obtained simply by extending an existing sequent calculus for bi-intuitionistic logic with typical inference ... More
Bounded Geometry and Characterization of post-singularly Finite $(p,q)$-Exponential MapsSep 26 2012Sep 14 2013In this paper we define a topological class of branched covering maps of the plane called {\em topological exponential maps of type $(p,q)$} and denoted by $\TE_{p,q}$, where $p\geq 0$ and $q\geq 1$. We follow the framework given in \cite{Ji} to study ... More
Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color CentersSep 04 2015Oct 26 2015We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV$^-$) color centers in diamond as quantum emitters. Hybrid SiC/diamond structures are realized by ... More
Exploring Cosmic Origins with CORE: InflationDec 25 2016Apr 05 2017We forecast the scientific capabilities to improve our understanding of cosmic inflation of CORE, a proposed CMB space satellite submitted in response to the ESA fifth call for a medium-size mission opportunity. The CORE satellite will map the CMB anisotropies ... More
Exploring Cosmic Origins with CORE: Cosmological ParametersNov 30 2016Apr 05 2017We forecast the main cosmological parameter constraints achievable with the CORE space mission which is dedicated to mapping the polarisation of the Cosmic Microwave Background (CMB). CORE was recently submitted in response to ESA's fifth call for medium-sized ... More
Failure of hydrogenation in protecting polycyclic aromatic hydrocarbons from fragmentationOct 27 2015A recent study of soft X-ray absorption in native and hydrogenated coronene cations, C$_{24}$H$_{12+m}^+$ $m=0-7$, led to the conclusion that additional hydrogen atoms protect (interstellar) Polycyclic Aromatic Hydrocarbon (PAH) molecules from fragmentation ... More
Are Dusty Galaxies Blue? Insights on UV Attenuation from Dust-Selected GalaxiesOct 02 2014Galaxies' rest-frame ultraviolet (UV) properties are often used to directly infer the degree to which dust obscuration affects the measurement of star formation rates. While much recent work has focused on calibrating dust attenuation in galaxies selected ... More
Cross-correlation between the CMB lensing potential measured by Planck and high-z sub-mm galaxies detected by the Herschel-ATLAS surveyOct 16 2014Apr 23 2015We present the first measurement of the correlation between the map of the cosmic microwave background (CMB) lensing potential derived from the \emph{Planck} nominal mission data and $z\gtrsim 1.5$ galaxies detected by the \emph{Herschel}-ATLAS (H-ATLAS) ... More
The Herschel-ATLAS: magnifications and physical sizes of $500\,μ$m-selected strongly lensed galaxiesJan 05 2018We perform lens modelling and source reconstruction of Submillimeter Array (SMA) data for a sample of 12 strongly lensed galaxies selected at 500$\mu$m in the Herschel Astrophysical Terahertz Large Area Survey H-ATLAS. A previous analysis of the same ... More
Submodularity in Input Node Selection for Networked SystemsMay 31 2016Networked systems are systems of interconnected components, in which the dynamics of each component are influenced by the behavior of neighboring components. Examples of networked systems include biological networks, critical infrastructures such as power ... More
Multiple interfaces in diffusional phase transitions in binary mesogen-non-mesogen mixtures undergoing metastable phase separationsOct 31 2013Theory and simulations of simultaneous chemical demixing and phase ordering are performed for a mixed order parameter system with an isotropic-isotropic (I-I) phase separation that is metastable with respect to an isotropic-nematic (I-N) phase ordering ... More
The post-nova populationOct 10 2011We here present our on-going project to unveil the post-nova population by re-discovering old novae that have been lost after the initial outburst and of which the binary itself is unobserved. We take UBVR photometry for the candidate selection, long-slit ... More
V2051 Oph after superoutburst: out-of-plane material and the superhump light sourceApr 06 2008We performed a detailed spectroscopic analysis of the dwarf nova V2051 Oph at the end of its 1999 superoutburst. We studied and interpreted the simultaneous behaviour of various emission lines. We obtained high-resolution echelle spectroscopic data at ... More
Optical and near-infrared velocity dispersions of early-type galaxiesNov 16 2010Nov 24 2010We have carried out a systematic, homogeneous comparison of optical and near-infrared dispersions. Our magnitude-limited sample of early-type galaxies in the Fornax cluster comprises 11 elliptical and 11 lenticular galaxies more luminous than MB = -17. ... More
Heat dissipation in atomic-scale junctionsJul 31 2013Atomic and single-molecule junctions represent the ultimate limit to the miniaturization of electrical circuits. They are also ideal platforms to test quantum transport theories that are required to describe charge and energy transfer in novel functional ... More
Effect of LOS/NLOS Propagation on Area Spectral Efficiency and Energy Efficiency of Small-CellsSep 26 2014In this paper we investigate the effect of Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS) propagation on the Area Spectral Efficiency (ASE) and on the energy efficiency of dense small-cell networks. We show that including both LOS and NLOS propagation ... More
Test of the semischematic model for a liquid of linear moleculesApr 09 1998We apply to a liquid of linear molecules the semischematic mode-coupling model, previously introduced to describe the center of mass (COM) slow dynamics of a network-forming molecular liquid. We compare the theoretical predictions and numerical results ... More
Supercooled Water and the Kinetic Glass Transition II: Collective DynamicsJun 05 1997In this article we study in detail the Q-vector dependence of the collective dynamics in simulated deeply supercooled SPC/E water. The evolution of the system has been followed for 250 ns at low T, allowing a clear identification of a two step relaxation ... More
Product Formalisms for Measures on Spaces with Binary Tree Structures: Representation, Visualization, and Multiscale NoiseJan 12 2016Nov 04 2016In this paper we focus on measures defined on dyadic sets which are sets with an ordered binary tree of subsets. An example is the partition of the unit interval into dyadic subintervals. The measures are defined on the sigma algebra generated by the ... More
Minimizing Convergence Error in Multi-Agent Systems via Leader Selection: A Supermodular Optimization ApproachJun 20 2013Nov 03 2013In a leader-follower multi-agent system (MAS), the leader agents act as control inputs and influence the states of the remaining follower agents. The rate at which the follower agents converge to their desired states, as well as the errors in the follower ... More
Adaptive Mitigation of Multi-Virus Propagation: A Passivity-Based ApproachMar 14 2016Sep 20 2016Malware propagation poses a growing threat to networked systems such as computer networks and cyber-physical systems. Current approaches to defending against malware propagation are based on patching or filtering susceptible nodes at a fixed rate. When ... More
A Unified Approach to Attractor ReconstructionFeb 23 2006Jun 30 2006In the analysis of complex, nonlinear time series, scientists in a variety of disciplines have relied on a time delayed embedding of their data, i.e. attractor reconstruction. The process has focused primarily on heuristic and empirical arguments for ... More
Finite element model selection using Particle Swarm OptimizationOct 12 2009This paper proposes the application of particle swarm optimization (PSO) to the problem of finite element model (FEM) selection. This problem arises when a choice of the best model for a system has to be made from set of competing models, each developed ... More
Bayesian evidence for finite element model updatingOct 15 2008This paper considers the problem of model selection within the context of finite element model updating. Given that a number of FEM updating models, with different updating parameters, can be designed, this paper proposes using the Bayesian evidence statistic ... More
Non-Linear Matter Power Spectrum Covariance Matrix Errors and Cosmological Parameter UncertaintiesDec 16 2015Apr 13 2016The covariance matrix of the matter power spectrum is a key element of the statistical analysis of galaxy clustering data. Independent realisations of observational measurements can be used to sample the covariance, nevertheless statistical sampling errors ... More
Thermodynamic Modelling of Phase Equilibrium in Nanoparticles-Nematic Liquid Crystals CompositesOct 31 2013In this work, a theoretical study of phase equilibrium in mixtures of a calamitic nematic liquid crystal and hard spherical nanoparticles is presented. A mean-field thermodynamic model is used, where the interactions are considered to be proportional ... More
Input Selection for Performance and Controllability of Structured Linear Descriptor SystemsDec 12 2014A common approach to controlling complex networks is to directly control a subset of input nodes, which then controls the remaining nodes via network interactions. While techniques have been proposed for selecting input nodes based on either performance ... More
The kinematics of lopsided galaxiesDec 13 2001Lopsidedness is a common feature in galaxies, both in the distribution of light and in the kinematics. We investigate the kinematics of a model for lopsided galaxies that consists of a disc lying off-centre in a dark halo, and circling around the halo ... More
Bayes Nets in Educational Assessment: Where Do the Numbers Come From?Jan 23 2013As observations and student models become complex, educational assessments that exploit advances in technology and cognitive psychology can outstrip familiar testing models and analytic methods. Within the Portal conceptual framework for assessment design, ... More
ALMA observations of lensed Herschel sources : Testing the dark-matter halo paradigmJan 22 2018With the advent of wide-area submillimeter surveys, a large number of high-redshift gravitationally lensed dusty star-forming galaxies (DSFGs) has been revealed. Due to the simplicity of the selection criteria for candidate lensed sources in such surveys, ... More
The RESOLVE Survey Atomic Gas Census and Environmental Influences on Galaxy Gas ReservoirsOct 21 2016Nov 01 2016We present the HI mass inventory for the RESOLVE survey, a volume-limited, multi-wavelength census of >1500 z=0 galaxies spanning diverse environments and complete in baryonic mass down to dwarfs of 10^9 Msun. This first 21cm data release provides robust ... More
HerMES: Clusters of Dusty Galaxies Uncovered by Herschel and PlanckNov 22 2013The potential for Planck to detect clusters of dusty, star-forming galaxies at z greater than 1 is tested by examining the Herschel-SPIRE images of Planck Early Release Compact Source Catalog (ERCSC) sources lying in fields observed by the HerMES survey. ... More
H-ATLAS: PACS imaging for the Science Demonstration PhaseSep 01 2010Sep 06 2010We describe the reduction of data taken with the PACS instrument on board the Herschel Space Observatory in the Science Demonstration Phase of the Herschel-ATLAS (H-ATLAS) survey, specifically data obtained for a 4x4-deg^2 region using Herschel's fast-scan ... More
{\em Herschel}-ATLAS/GAMA: The Environmental Density of Far-Infrared Bright Galaxies at $z \leq 0.5$May 02 2013We compare the environmental and star formation properties of far-infrared detected and non--far-infrared detected galaxies out to $z \sim0.5$. Using optical spectroscopy and photometry from the Galaxy And Mass Assembly (GAMA) and Sloan Digital Sky Survey ... More
Upper limits for undetected trace species in the stratosphere of TitanMar 01 2011In this paper we describe a first quantitative search for several molecules in Titan's stratosphere in Cassini CIRS infrared spectra. These are: ammonia (NH3), methanol (CH3OH), formaldehyde (H2CO), and acetonitrile (CH3CN), all of which are predicted ... More
Hierarchical Star Formation in Nearby LEGUS GalaxiesApr 24 2014Hierarchical structure in ultraviolet images of 12 late-type LEGUS galaxies is studied by determining the numbers and fluxes of nested regions as a function of size from ~1 to ~200 pc, and the number as a function of flux. Two starburst dwarfs, NGC 1705 ... More
Where stars form: inside-out growth and coherent star formation from HST Halpha maps of 2676 galaxies across the main sequence at z~1Jul 14 2015We present Ha maps at 1kpc spatial resolution for star-forming galaxies at z~1, made possible by the WFC3 grism on HST. Employing this capability over all five 3D-HST/CANDELS fields provides a sample of 2676 galaxies. By creating deep stacked Halpha (Ha) ... More
Millimeter mapping at z~1: dust-obscured bulge building and disk growthJan 08 2018A randomly chosen star in today's Universe is most likely to live in a galaxy with a stellar mass between that of the Milky Way and Andromeda. Yet it remains uncertain how the structural evolution of these bulge-disk systems proceeded. Most of the unobscured ... More
NaSt1: A Wolf-Rayet star cloaked by an eta Car--like nebula?Mar 26 1999We present a study of the peculiar Galactic emission line object NaSt1 (WR122, IRAS 18497+0056) which has previously been classified as a Wolf-Rayet (WR) star. Our spectroscopic dataset comprises Keck I-HIRES, WHT-ISIS and UKIRT-CGS4 observations which ... More
A relativistic jetted outburst from a massive black hole fed by a tidally disrupted starApr 16 2011While gas accretion onto some massive black holes (MBHs) at the centers of galaxies actively powers luminous emission, the vast majority of MBHs are considered dormant. Occasionally, a star passing too near a MBH is torn apart by gravitational forces, ... More